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1.  Reduction in Red Blood Cell Transfusions Among Preterm Infants: Results of a Randomized Trial With an In-Line Blood Gas and Chemistry Monitor 
Pediatrics  2005;115(5):1299-1306.
Critically ill, extremely premature infants develop anemia because of intensive laboratory blood testing and undergo multiple red blood cell (RBC) transfusions in the early weeks of life. To date, researchers have had only limited success in finding ways to reduce transfusions significantly in this patient population.
To reduce RBC transfusions for these infants by using a point-of-care bedside monitor that returns analyzed blood to the patient.
Design, Setting, and Patients
This was a prospective, 2-center, randomized, open, controlled, clinical trial with a 1:1 assignment of extremely low birth weight infants (weighing 500–1000 g at birth) to control or monitor groups and analysis with the intention-to-treat approach. Predefined RBC transfusion criteria were applied uniformly in the 2 groups.
Clinical treatment of study subjects with an in-line, ex vivo, bedside monitor that withdraws blood through an umbilical artery catheter, analyzes blood gases and sodium, potassium, and hematocrit levels, and returns the sample to the patient.
Main Outcome Measures
The total volume and number of RBC transfusions during the first 2 weeks of life and the total volume of blood removed for laboratory testing.
The trial was terminated prematurely when one center's NICU changed its standard method of laboratory testing. In the first 2 weeks of life, there was a nonsignificant 17% lower cumulative RBC transfusion volume in the monitor group (n = 46), compared with the control group (n = 47). However, data from the first week only (the period of greater catheter use) demonstrated a significant 33% lower cumulative RBC transfusion volume in the monitor group. Cumulative phlebotomy loss was ~25% less in the monitor group throughout the 2-week study period. There was no difference between groups in neonatal mortality, morbidity, and neurodevelopmental outcome rates at 18 to 24 months. This is the first randomized trial documenting that RBC transfusions administered to neonates can by reduced by decreasing laboratory phlebotomy loss.
As long as an umbilical artery catheter is available for blood sampling with an in-line blood gas and chemistry monitor, significant reductions in neonatal RBC transfusions can be achieved. The patients most likely to benefit from monitor use are the smallest, most critically ill newborns.
PMCID: PMC2867083  PMID: 15867038
2.  Effects of Race/Ethnicity and BMI on the Association between Height and Risk for Spontaneous Preterm Birth 
Short height and obesity have each been associated with increased risk for preterm birth (PTB). However, the effect of short height on PTB risk, across different race/ethnicities and BMI categories, has not been studied. Our objective was to determine the influence of maternal height on the risk for PTB within race/ethnic groups, BMI groups, or adjusted for weight.
All California singleton, live births between 2007–2010 were included from birth certificate data (vital statistics) linked to hospital discharge data. Pre-pregnancy BMI (kg/m2) was categorized as underweight (< 18.5); normal (18.5–24.9); overweight (25.0–29.9) or obese (≥30.0). Maternal race/ethnicity was categorized as: Non-Hispanic White, Non-Hispanic Black, Hispanic and Asian. Maternal height was classified into 5 categories (shortest, short, middle, tall, tallest) based on racial/ethnic-specific height distributions, with the middle category serving as reference. Poisson regression models were used to estimate relative risks (RR) for the association between maternal height and risk of spontaneous PTB (< 37 weeks and < 32 weeks). Models were stratified on race/ethnicity and BMI. Generalized additive regression models (GAM) were used to detect nonlinearity of the association. Covariates considered were: maternal age, weight, parity, prenatal care, education, medical payment, previous PTB, gestational and pre-gestational diabetes, pre-gestational hypertension, preeclampsia/eclampsia, and smoking.
Among 1,655,385 California singleton live births, 5.2% were spontaneous preterm births < 37 weeks. Short stature (1st height category) was associated with increased risk for PTB for Non-Hispanic Whites and Hispanics across all BMI categories. Among obese women, tall stature (5th category) was associated with reduced risk for spontaneous PTB for Non-Hispanic Whites, Asians and Hispanics. Same pattern of association was seen for height and risk for spontaneous PTB < 32 weeks. In the GAM plots, short stature was associated with increased risk for spontaneous PTB of < 32 and <37 weeks of gestation among Whites and Asians. However, this association was not observed for Blacks and Hispanics.
Maternal shorter height is associated with a modest increased risk for spontaneous PTB regardless of BMI. Our results suggest that PTB risk assessment should consider race/ethnicity specific height with respect to the norm in addition to BMI assessment.
PMCID: PMC4631690  PMID: 26187451
Maternal height; Race/ethnicity; BMI; spontaneous preterm birth
3.  Failed Endotracheal Intubation and Adverse Outcomes Among Extremely Low Birth Weight Infants 
To quantify the importance of successful endotracheal intubation on the first attempt among extremely low birth weight (ELBW) infants who require resuscitation after delivery.
A retrospective chart review was conducted for all ELBW infants ≤1000 g born between January 2007 and May 2014 at a level IV neonatal intensive care unit. Infants were included if intubation was attempted during the first five minutes of life, or if intubation was attempted during the first 10 minutes of life with heart rate < 100. The primary outcome was death or neurodevelopmental impairment. The association between successful intubation on the first attempt and the primary outcome was assessed using multivariable logistic regression with adjustment for birth weight, gestational age, gender, and antenatal steroids.
The study sample included 88 ELBW infants. Forty-percent were intubated on the first attempt and 60% required multiple intubation attempts. Death or neurodevelopmental impairment occurred in 29% of infants intubated on the first attempt, compared to 53% of infants that required multiple attempts, adjusted odds ratio 0.4 (95% confidence interval 0.1 - 1.0), p < 0.05.
Successful intubation on the first attempt is associated with improved neurodevelopmental outcomes among ELBW infants. This study confirms the importance of rapid establishment of a stable airway in ELBW infants requiring resuscitation after birth and has implications for personnel selection and role assignment in the delivery room.
PMCID: PMC4731260  PMID: 26540244
Extremely low birth weight; endotracheal intubation; neurodevelopmental impairment; resuscitation; failed intubation; intubation attempt
4.  Exome Sequencing of Neonatal Blood Spots and the Identification of Genes Implicated in Bronchopulmonary Dysplasia 
Rationale: Bronchopulmonary dysplasia (BPD), a prevalent severe lung disease of premature infants, has a strong genetic component. Large-scale genome-wide association studies for common variants have not revealed its genetic basis.
Objectives: Given the historical high mortality rate of extremely preterm infants who now survive and develop BPD, we hypothesized that risk loci underlying this disease are under severe purifying selection during evolution; thus, rare variants likely explain greater risk of the disease.
Methods: We performed exome sequencing on 50 BPD-affected and unaffected twin pairs using DNA isolated from neonatal blood spots and identified genes affected by extremely rare nonsynonymous mutations. Functional genomic approaches were then used to systematically compare these affected genes.
Measurements and Main Results: We identified 258 genes with rare nonsynonymous mutations in patients with BPD. These genes were highly enriched for processes involved in pulmonary structure and function including collagen fibril organization, morphogenesis of embryonic epithelium, and regulation of Wnt signaling pathway; displayed significantly elevated expression in fetal and adult lungs; and were substantially up-regulated in a murine model of BPD. Analyses of mouse mutants revealed their phenotypic enrichment for embryonic development and the cyanosis phenotype, a clinical manifestation of BPD.
Conclusions: Our study supports the role of rare variants in BPD, in contrast with the role of common variants targeted by genome-wide association studies. Overall, our study is the first to sequence BPD exomes from newborn blood spot samples and identify with high confidence genes implicated in BPD, thereby providing important insights into its biology and molecular etiology.
PMCID: PMC4595691  PMID: 26030808
exome sequencing; chronic lung disease; bronchopulmonary dysplasia; genetic predisposition to disease; premature
5.  Heme Oxygenase-1 Expression Affects Murine Abdominal Aortic Aneurysm Progression 
PLoS ONE  2016;11(2):e0149288.
Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme degradation, is a cytoprotective enzyme upregulated in the vasculature by increased flow and inflammatory stimuli. Human genetic data suggest that a diminished HO-1 expression may predispose one to abdominal aortic aneurysm (AAA) development. In addition, heme is known to strongly induce HO-1 expression. Utilizing the porcine pancreatic elastase (PPE) model of AAA induction in HO-1 heterozygous (HO-1+/-, HO-1 Het) mice, we found that a deficiency in HO-1 leads to augmented AAA development. Peritoneal macrophages from HO-1+/- mice showed increased gene expression of pro-inflammatory cytokines, including MCP-1, TNF-alpha, IL-1-beta, and IL-6, but decreased expression of anti-inflammatory cytokines IL-10 and TGF-beta. Furthermore, treatment with heme returned AAA progression in HO-1 Het mice to a wild-type profile. Using a second murine AAA model (Ang II-ApoE-/-), we showed that low doses of the HMG-CoA reductase inhibitor rosuvastatin can induce HO-1 expression in aortic tissue and suppress AAA progression in the absence of lipid lowering. Our results support those studies that suggest that pleiotropic statin effects might be beneficial in AAA, possibly through the upregulation of HO-1. Specific targeted therapies designed to induce HO-1 could become an adjunctive therapeutic strategy for the prevention of AAA disease.
PMCID: PMC4760983  PMID: 26894432
6.  Implementing Mass Cytometry at the Bedside to Study the Immunological Basis of Human Diseases: Distinctive Immune Features in Patients with a History of Term or Preterm Birth 
Single-cell technologies have immense potential to shed light on molecular and biological processes that drive human diseases. Mass cytometry (or Cytometry by Time Of Flight mass spectrometry, CyTOF) has already been employed in clinical studies to comprehensively survey patients’ circulating immune system. As interest in the “bedside” application of mass cytometry is growing, the delineation of relevant methodological issues is called for. This report uses a newly generated dataset to discuss important methodological considerations when mass cytometry is implemented in a clinical study. Specifically, the use of whole blood samples versus peripheral blood mononuclear cells (PBMCs), design of mass-tagged antibody panels, technical and analytical implications of sample barcoding, and application of traditional and unsupervised approaches to analyze high-dimensional mass cytometry datasets are discussed. A mass cytometry assay was implemented in a cross-sectional study of 19 women with a history of term or preterm birth to determine whether immune traits in peripheral blood differentiate the two groups in the absence of pregnancy. Twenty-seven phenotypic and 11 intracellular markers were simultaneously analyzed in whole blood samples stimulated with lipopolysaccharide (LPS at 0, 0.1, 1, 10, and 100 ng mL−1) to examine dose-dependent signaling responses within the toll-like receptor 4 (TLR4) pathway. Complementary analyses, grounded in traditional or unsupervised gating strategies of immune cell subsets, indicated that the prpS6 and pMAPKAPK2 responses in classical monocytes are accentuated in women with a history of preterm birth (FDR<1%). The results suggest that women predisposed to preterm birth may be prone to mount an exacerbated TLR4 response during the course of pregnancy. This important hypothesis-generating finding points to the power of single-cell mass cytometry to detect biologically important differences in a relatively small patient cohort.
PMCID: PMC4758855  PMID: 26190063
mass cytometry; CyTOF; clinical applications; innate immunity; single cell; preterm birth; monocytes; TLR4
7.  Neuroimaging and Neurodevelopmental Outcome in Extremely Preterm Infants 
Pediatrics  2015;135(1):e32-e42.
Extremely preterm infants are at risk for neurodevelopmental impairment (NDI). Early cranial ultrasound (CUS) is usual practice, but near-term brain MRI has been reported to better predict outcomes. We prospectively evaluated MRI white matter abnormality (WMA) and cerebellar lesions, and serial CUS adverse findings as predictors of outcomes at 18 to 22 months’ corrected age.
Early and late CUS, and brain MRI were read by masked central readers, in a large cohort (n = 480) of infants <28 weeks’ gestation surviving to near term in the Neonatal Research Network. Outcomes included NDI or death after neuroimaging, and significant gross motor impairment or death, with NDI defined as cognitive composite score <70, significant gross motor impairment, and severe hearing or visual impairment. Multivariable models evaluated the relative predictive value of neuroimaging while controlling for other factors.
Of 480 infants, 15 died and 20 were lost. Increasing severity of WMA and significant cerebellar lesions on MRI were associated with adverse outcomes. Cerebellar lesions were rarely identified by CUS. In full multivariable models, both late CUS and MRI, but not early CUS, remained independently associated with NDI or death (MRI cerebellar lesions: odds ratio, 3.0 [95% confidence interval: 1.3–6.8]; late CUS: odds ratio, 9.8 [95% confidence interval: 2.8–35]), and significant gross motor impairment or death. In models that did not include late CUS, MRI moderate-severe WMA was independently associated with adverse outcomes.
Both late CUS and near-term MRI abnormalities were associated with outcomes, independent of early CUS and other factors, underscoring the relative prognostic value of near-term neuroimaging.
PMCID: PMC4279063  PMID: 25554820
MRI; neurodevelopmental; neuroimaging; preterm infant; ultrasound
8.  Role of infant sex in the association between air pollution and preterm birth 
Annals of epidemiology  2015;25(11):874-876.
PMCID: PMC4671488  PMID: 26475983
Preterm birth; Air pollution; Sex differences
9.  Traffic-Related Air Pollution and Risk of Preterm Birth in the San Joaquin Valley of California 
Annals of epidemiology  2014;24(12):888-95e4.
We evaluated associations between traffic-related air pollution during pregnancy and preterm birth in births in four counties in California during years 2000–2006. We used logistic regression to examine the association between the highest quartile of ambient air pollutants (carbon monoxide, nitrogen dioxide, particulate matter <10 and 2.5 μm) and traffic density during pregnancy and each of five levels of prematurity based on gestational age at birth (20–23, 24–27, 28–31, 32–33 and 34–36 weeks) versus term (37–42 weeks). We examined trimester averages and the last month and last 6 weeks of pregnancy. Models were adjusted for birth weight, maternal age, race/ethnicity, education, prenatal care and birth costs payment. Neighborhood socioeconomic status was evaluated as a potential effect modifier. There were increased odds ratios for early preterm birth for those exposed to the highest quartile of each pollutant during the second trimester and the end of pregnancy (adjusted odds ratios: 1.4– 2.8). Associations were stronger among mothers living in low socioeconomic status neighborhoods (adjusted odds ratios: 2.1–4.3). We observed exposure-response associations for multiple pollutant exposures and early preterm birth. Inverse associations during the first trimester were observed. The results confirm associations between traffic-related air pollution and prematurity, particularly among very early preterm births and low socioeconomic status neighborhoods.
PMCID: PMC4355392  PMID: 25453347
air pollution; preterm birth; pregnancy
10.  Prepregnancy Obesity and Risks of Stillbirth 
PLoS ONE  2015;10(10):e0138549.
We examined the association of maternal obesity with risk of stillbirth, focusing on whether the pattern of results varied by gestational age or maternal race-ethnicity or parity.
Analyses included 4,012 stillbirths and 1,121,234 liveborn infants delivered in California from 2007–2010. We excluded stillbirths due to congenital anomalies, women with hypertensive disorders or diabetes, and plural births, to focus on fetuses and women without these known contributing conditions. We used Poisson regression to estimate relative risks (RR) and 95% confidence intervals (CI). Separate models were run for stillbirths delivered at 20–23, 24–27, 28–31, 32–36, 37–41 weeks, relative to liveborn deliveries at 37–41 weeks.
For stillbirth at 20–23 weeks, RRs were elevated for all race-ethnicity and parity groups. The RR for a 20-unit change in BMI (which reflects the approximate BMI difference between a normal weight and an Obese III woman) was 3.5 (95% CI 2.2, 5.6) for nulliparous white women and ranged from 1.8 to 5.0 for other sub-groups. At 24–27 weeks, the association was significant (p<0.05) only for multiparous non-Hispanic whites; at 28–31 weeks, for multiparous whites and nulliparous whites and blacks; at 32–36 weeks, for multiparous whites and nulliparous blacks; and at 37–41 weeks, for all groups except nulliparous blacks. The pattern of results was similar when restricted to stillbirths due to unknown causes and somewhat stronger when restricted to stillbirths attributable to obstetric causes.
Increased risks were observed across all gestational ages, and some evidence of heterogeneity of the associations was observed by race-ethnicity and parity.
PMCID: PMC4605840  PMID: 26466315
11.  Death or Neurodevelopmental Impairment at 18 To 22 Months in a Randomized Trial of Early Dexamethasone to Prevent Death or Chronic Lung Disease in Extremely Low Birth Weight Infants 
The Journal of pediatrics  2013;164(1):34-39.e2.
To evaluate the incidence of death or neurodevelopmental impairment (NDI) at 18 to 22 months corrected age in subjects enrolled in a trial of early dexamethasone treatment to prevent death or chronic lung disease in extremely low birth weight infants.
Evaluation of infants at 18 to 22 months corrected age included anthropomorphic measurements, a standard neurological examination, and the Bayley Scales of Infant Development-II, including the Mental Developmental Index (MDI) and the Psychomotor Developmental Index (PDI). NDI was defined as moderate or severe cerebral palsy, MDI or PDI less than 70, blindness, or hearing impairment.
Death or NDI at 18 to 22 months corrected age was similar in the dexamethasone and placebo groups (65 vs 66 percent, p= 0.99 among those with known outcome). The proportion of survivors with NDI was also similar, as were mean values for weight, length, and head circumference and the proportion of infants with poor growth (50 vs 41 percent, p=0.42 for weight less than 10th percentile). Forty nine percent of infants in the placebo group received treatment with corticosteroid compared to 32% in the dexamethasone group (p=0.02).
The risk of death or NDI and rate of poor growth were high but similar in the dexamethasone and placebo groups. The lack of a discernible effect of early dexamethasone on neurodevelopmental outcome may be due to frequent clinical corticosteroid use in the placebo group.
PMCID: PMC4120744  PMID: 23992673
neurodevelopmental outcome; growth; bronchopulmonary dysplasia; cerebral palsy; neonatal follow-up
12.  Copy Number Variation in Bronchopulmonary Dysplasia 
PMCID: PMC4167221  PMID: 24975634
copy number variation; genome-wide association study (GWAS); chronic lung disease of infancy; bronchopulmonary dysplasia; genetic predisposition to disease; premature; very low birth weight infant
13.  Elevated tumor necrosis factor-alpha (TNF-α) and hyperlipidemia in pregnancies resulting in early preterm birth 
To determine whether pregnancies resulting in early preterm birth (< 30 weeks) were more likely than term pregnancies to have elevated mid-trimester tumor necrosis factor alpha (TNF-α) levels co-occurring with lipid patterns suggestive of hyperlipidemia.
Study Design
Patterns were examined using stored non-fasted serum samples from 108 California and 734 Iowa singleton pregnancies collected as part of statewide prenatal screening. The frequency of elevated mid-pregnancy serum TNF-α levels and lipid patterns suggestive of hyperlipidemia (e.g. elevated total cholesterol (TC), low-density-lipoproteins (LDLs), or triglycerides (TGs), decreased high-density lipoproteins (HDLs)) (considered independently and by co-occurrence) were compared in pregnancies resulting in early preterm birth to those resulting in term birth using logistic regression models.
While no differences between preterm and term pregnancies were evident when TNF-α or target lipid abnormalities occurred in isolation, early preterm pregnancies were two to four times more likely than term pregnancies to have elevated TNF-α levels co-occurring with indicators of hyperlipidemia (37.5% versus 13.9% in the California sample (adjusted OR 4.0, 95% CI 1.1 – 16.3) and 26.3% versus 14.9% in the Iowa sample (adjusted OR 2.7, 95% CI 1.1 – 6.3)). Observed differences were not explicable to any maternal or infant characteristics.
Pregnancies resulting in early preterm birth were more likely than term pregnancies to have elevated mid-pregnancy TNF-α levels co-occurring with lipid patterns suggestive of hyperlipidemia. Patterns offer clues for further study of the signaling of early parturition in preterm birth.
PMCID: PMC4117727  PMID: 24831886
14.  Prevention of Traumatic Stress in Mothers of Preterms: 6-Month Outcomes 
Pediatrics  2014;134(2):e481-e488.
Symptoms of posttraumatic stress disorder are a well-recognized phenomenon in mothers of preterm infants, with implications for maternal health and infant outcomes. This randomized controlled trial evaluated 6-month outcomes from a skills-based intervention developed to reduce symptoms of posttraumatic stress disorder, anxiety, and depression.
One hundred five mothers of preterm infants were randomly assigned to (1) a 6- or 9-session intervention based on principles of trauma-focused cognitive behavior therapy with infant redefinition or (2) a 1-session active comparison intervention based on education about the NICU and parenting of the premature infant. Outcome measures included the Davidson Trauma Scale, the Beck Depression Inventory II, and the Beck Anxiety Inventory. Participants were assessed at baseline, 4 to 5 weeks after birth, and 6 months after the birth of the infant.
At the 6-month assessment, the differences between the intervention and comparison condition were all significant and sizable and became more pronounced when compared with the 4- to 5-week outcomes: Davidson Trauma Scale (Cohen's d = −0.74, P < .001), Beck Anxiety Inventory (Cohen's d = −0.627, P = .001), Beck Depression Inventory II (Cohen's d = −0.638, P = .002). However, there were no differences in the effect sizes between the 6- and 9-session interventions.
A brief 6-session intervention based on principles of trauma-focused cognitive behavior therapy was effective at reducing symptoms of trauma, anxiety, and depression in mothers of preterm infants. Mothers showed increased benefits at the 6-month follow-up, suggesting that they continue to make use of techniques acquired during the intervention phase.
PMCID: PMC4187238  PMID: 25049338
neonatal intensive care; premature infants; posttraumatic stress disorder; intervention; PTSD; preterm infants; neonatal ICU; intervention
16.  Safety and Efficacy of Filtered Sunlight in Treatment of Jaundice in African Neonates 
Pediatrics  2014;133(6):e1568-e1574.
Evaluate safety and efficacy of filtered-sunlight phototherapy (FS-PT).
Term/late preterm infants ≤14 days old with clinically significant jaundice, assessed by total bilirubin (TB) levels, were recruited from a maternity hospital in Lagos, Nigeria. Sunlight was filtered with commercial window-tinting films that remove most UV and significant levels of infrared light and transmit effective levels of therapeutic blue light. After placing infants under an FS-PT canopy, hourly measurements of axillary temperatures, monitoring for sunburn, dehydration, and irradiances of filtered sunlight were performed. Treatment was deemed safe and efficacious if infants were able to stay in FS-PT for ≥5 hours and rate of rise of TB was <0.2 mg/dL/h for infants ≤72 hours of age or TB decreased for infants >72 hours of age.
A total of 227 infants received 258 days of FS-PT. No infant developed sunburn or dehydration. On 85 (33%) of 258 treatment days, infants were removed briefly from FS-PT due to minor temperature-related adverse events. No infant met study exit criteria. FS-PT was efficacious in 92% (181/197) of evaluable treatment days. Mean ± SD TB change was –0.06 ± 0.19 mg/dL/h. The mean ± SD (range) irradiance of FS-PT was 38 ± 22 (2–115) µW/cm2/nm, measured by the BiliBlanket Meter II.
With appropriate monitoring, filtered sunlight is a novel, practical, and inexpensive method of PT that potentially offers safe and efficacious treatment strategy for management of neonatal jaundice in tropical countries where conventional PT treatment is not available.
PMCID: PMC4531268  PMID: 24864170
newborn jaundice; hyperbilirubinemia; sunlight; phototherapy; irradiance; UV; IR; low-middle income countries
17.  Heme oxygenase and the immune system in normal and pathological pregnancies 
Normal pregnancy is an immunotolerant state. Many factors, including environmental, socioeconomic, genetic, and immunologic changes by infection and/or other causes of inflammation, may contribute to inter-individual differences resulting in a normal or pathologic pregnancy. In particular, imbalances in the immune system can cause many pregnancy-related diseases, such as infertility, abortions, pre-eclampsia, and preterm labor, which result in maternal/fetal death, prematurity, or small-for-gestational age newborns. New findings imply that myeloid regulatory cells and regulatory T cells (Tregs) may mediate immunotolerance during normal pregnancy. Effector T cells (Teffs) have, in contrast, been implicated to cause adverse pregnancy outcomes. Furthermore, feto-maternal tolerance affects the developing fetus. It has been shown that the Treg/Teff balance affects litter size and adoptive transfer of pregnancy-induced Tregs can prevent fetal rejection in the mouse. Heme oxygenase-1 (HO-1) has a protective role in many conditions through its anti-inflammatory, anti-apoptotic, antioxidative, and anti-proliferative actions. HO-1 is highly expressed in the placenta and plays a role in angiogenesis and placental vascular development and in regulating vascular tone in pregnancy. In addition, HO-1 is a major regulator of immune homeostasis by mediating crosstalk between innate and adaptive immune systems. Moreover, HO-1 can inhibit inflammation-induced phenotypic maturation of immune effector cells and pro-inflammatory cytokine secretion and promote anti-inflammatory cytokine production. HO-1 may also be associated with T-cell activation and can limit immune-based tissue injury by promoting Treg suppression of effector responses. Thus, HO-1 and its byproducts may protect against pregnancy complications by its immunomodulatory effects, and the regulation of HO-1 or its downstream effects has the potential to prevent or treat pregnancy complications and prematurity.
PMCID: PMC4408852  PMID: 25964759
fetus; HO-1; immunomodulation; immunotolerance; newborn; placenta; pregnancy
18.  Investigation of maternal environmental exposures in association with self-reported preterm birth 
Identification of maternal environmental factors influencing preterm birth risks is important to understand the reasons for the increase in prematurity since 1990. Here, we utilized a health survey, the US National Health and Nutrition Examination Survey (NHANES) to search for personal environmental factors associated with preterm birth. 201 urine and blood markers of environmental factors, such as allergens, pollutants, and nutrients were assayed in mothers (range of N: 49 to 724) who answered questions about any children born preterm (delivery <37 weeks). We screened each of the 201 factors for association with any child born preterm adjusting by age, race/ethnicity, education, and household income. We attempted to verify the top finding, urinary bisphenol A, in an independent study of pregnant women attending Lucile Packard Children’s Hospital. We conclude that the association between maternal urinary levels of bisphenol A and preterm birth should be evaluated in a larger epidemiological investigation.
PMCID: PMC4316205  PMID: 24373932
environmental exposure; environment-wide association study; preterm birth
19.  Heme oxygenase-1 in pregnancy and cancer: similarities in cellular invasion, cytoprotection, angiogenesis, and immunomodulation 
Pregnancy can be defined as a “permissible” process, where a semi-allogeneic fetus and placenta are allowed to grow and survive within the mother. Similarly, in tumor growth, antigen-specific malignant cells proliferate and evade into normal tissues of the host. The microenvironments of the placenta and tumors are amazingly comparable, sharing similar mechanisms exploited by fetal or cancer cells with regard to surviving in a hypoxic microenvironment, invading tissues via degradation and vasculogenesis, and escaping host attack through immune privilege. Heme oxygease-1 (HO-1) is a stress-response protein that has antioxidative, anti-apoptotic, pro-angiogenic, and anti-inflammatory properties. Although a large volume of research has been published in recent years investigating the possible role(s) of HO-1 in pregnancy and in cancer development, the molecular mechanisms that regulate these “yin-yang” processes have still not been fully elucidated. Here, we summarize and compare pregnancy and cancer development, focusing primarily on the function of HO-1 in cellular invasion, cytoprotection, angiogenesis, and immunomodulation. Due to the similarities of both processes, a thorough understanding of the molecular mechanisms of each process may reveal and guide the development of new approaches to prevent not only pregnancy disorders; but also, to study cancer.
PMCID: PMC4294126  PMID: 25642189
Placenta; trophoblast invasion; angiogenesis;  immunosuppression; tolerogenic dendritic cells (tDC); alternatively activated macrophage (M2)
20.  Immunogenicity of Haemophilus influenzae Type b Protein Conjugate Vaccines in Very Low Birth Weight Infants 
PMCID: PMC3960569  PMID: 24569312
Infant; premature; infant; very low birth weight; Haemophilus influenzae vacines; immunization; vaccines
21.  Prevention of Traumatic Stress in Mothers With Preterm Infants: A Randomized Controlled Trial 
Pediatrics  2013;132(4):e886-e894.
The current study evaluates a treatment intervention developed with the goal of reducing symptoms of posttraumatic stress, depression, and anxiety in parents of premature infants.
A total of 105 mothers of preterm infants (25–34 weeks’ gestational age; >600 g) were randomized to receive a 6-session intervention developed to target parental trauma as well as facilitate infant redefinition (n = 62) or to an active comparison group (n = 43). Mothers in the intervention group received a combination of trauma-focused treatments, including psychoeducation, cognitive restructuring, progressive muscle relaxation, and development of their trauma narrative. The intervention also incorporated material targeting infant redefinition, defined as the process of changing the mother’s negative perceptions of her infant and the parenting experience.
Mothers in the intervention group reported a greater reduction in both trauma symptoms (Cohen’s d = 0.41, P = .023) and depression (Cohen’s d = 0.59, P < .001) compared with the comparison group. Patients under both conditions improved significantly in terms of anxiety, with no differences between groups. Results of the moderator analysis showed that mothers with higher ratings of baseline NICU stress benefited more from the intervention compared with mothers who had lower ratings (P = .036).
This short, highly manualized intervention for mothers of preterm infants statistically significantly reduced symptoms of trauma and depression. The intervention is feasible, can be delivered with fidelity, and has high ratings of maternal satisfaction. Given that improvements in mothers’ distress may lead to improved infant outcomes, this intervention has the potential for a high public health impact.
PMCID: PMC3784295  PMID: 23999956
intervention; neonatal intensive care; premature infants; posttraumatic stress disorder
22.  Raltegravir In Vitro Effect on Bilirubin Binding 
The Pediatric infectious disease journal  2013;32(9):10.1097/INF.0b013e31829044a8.
Drugs that displace bilirubin from albumin may increase the risk of kernicterus in neonates. We evaluated the effect of raltegravir on bilirubin-albumin binding in pooled neonatal serum using the peroxidase method. Raltegravir had minimal effect on bilirubin-albumin binding at concentrations of 5 and 10 μM, caused a small but statistically significant increase in unbound bilirubin at 100 μM, and caused potentially harmful increases at 500 and 1000 μM. Our data suggest that the effect of raltegravir on neonatal bilirubin binding is unlikely to be clinically significant at typical peak concentrations reached with usual dosing.
PMCID: PMC3856729  PMID: 23470680
raltegravir; bilirubin binding; neonate
23.  A Genome-Wide Association Study (GWAS) for Bronchopulmonary Dysplasia 
Pediatrics  2013;132(2):290-297.
Twin studies suggest that heritability of moderate-severe bronchopulmonary dysplasia (BPD) is 53% to 79%, we conducted a genome-wide association study (GWAS) to identify genetic variants associated with the risk for BPD.
The discovery GWAS was completed on 1726 very low birth weight infants (gestational age = 250–296/7 weeks) who had a minimum of 3 days of intermittent positive pressure ventilation and were in the hospital at 36 weeks’ postmenstrual age. At 36 weeks’ postmenstrual age, moderate-severe BPD cases (n = 899) were defined as requiring continuous supplemental oxygen, whereas controls (n = 827) inhaled room air. An additional 795 comparable infants (371 cases, 424 controls) were a replication population. Genomic DNA from case and control newborn screening bloodspots was used for the GWAS. The replication study interrogated single-nucleotide polymorphisms (SNPs) identified in the discovery GWAS and those within the HumanExome beadchip.
Genotyping using genomic DNA was successful. We did not identify SNPs associated with BPD at the genome-wide significance level (5 × 10−8) and no SNP identified in previous studies reached statistical significance (Bonferroni-corrected P value threshold .0018). Pathway analyses were not informative.
We did not identify genomic loci or pathways that account for the previously described heritability for BPD. Potential explanations include causal mutations that are genetic variants and were not assayed or are mapped to many distributed loci, inadequate sample size, race ethnicity of our study population, or case-control differences investigated are not attributable to underlying common genetic variation.
PMCID: PMC3727675  PMID: 23897914
genome-wide association study (GWAS); chronic lung disease; genetic predisposition to disease; premature; very low birth weight infant
24.  Neonatal physiological correlates of near-term brain development on MRI and DTI in very-low-birth-weight preterm infants 
NeuroImage : Clinical  2014;5:169-177.
Structural brain abnormalities identified at near-term age have been recognized as potential predictors of neurodevelopment in children born preterm. The aim of this study was to examine the relationship between neonatal physiological risk factors and early brain structure in very-low-birth-weight (VLBW) preterm infants using structural MRI and diffusion tensor imaging (DTI) at near-term age.
Structural brain MRI, diffusion-weighted scans, and neonatal physiological risk factors were analyzed in a cross-sectional sample of 102 VLBW preterm infants (BW ≤ 1500 g, gestational age (GA) ≤ 32 weeks), who were admitted to the Lucile Packard Children's Hospital, Stanford NICU and recruited to participate prior to routine near-term brain MRI conducted at 36.6 ± 1.8 weeks postmenstrual age (PMA) from 2010 to 2011; 66/102 also underwent a diffusion-weighted scan. Brain abnormalities were assessed qualitatively on structural MRI, and white matter (WM) microstructure was analyzed quantitatively on DTI in six subcortical regions defined by DiffeoMap neonatal brain atlas. Specific regions of interest included the genu and splenium of the corpus callosum, anterior and posterior limbs of the internal capsule, the thalamus, and the globus pallidus. Regional fractional anisotropy (FA) and mean diffusivity (MD) were calculated using DTI data and examined in relation to neonatal physiological risk factors including gestational age (GA), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), and sepsis, as well as serum levels of C-reactive protein (CRP), glucose, albumin, and total bilirubin.
Brain abnormalities were observed on structural MRI in 38/102 infants including 35% of females and 40% of males. Infants with brain abnormalities observed on MRI had higher incidence of BPD (42% vs. 25%) and sepsis (21% vs. 6%) and higher mean and peak serum CRP levels, respectively, (0.64 vs. 0.34 mg/dL, p = .008; 1.57 vs. 0.67 mg/dL, p= .006) compared to those without. The number of signal abnormalities observed on structural MRI correlated to mean and peak CRP (rho = .316, p = .002; rho = .318, p= .002). The number of signal abnormalities observed on MRI correlated with thalamus MD (left: r= .382, p= .002; right: r= .400, p= .001), controlling for PMA-at-scan. Thalamus WM microstructure demonstrated the strongest associations with neonatal risk factors. Higher thalamus MD on the left and right, respectively, was associated with lower GA (r = −.322, p = .009; r= −.381, p= .002), lower mean albumin (r = −.276, p= .029; r= −.385, p= .002), and lower mean bilirubin (r = −.293, p= .020; r= −.337 p= .007).
Results suggest that at near-term age, thalamus WM microstructure may be particularly vulnerable to certain neonatal risk factors. Interactions between albumin, bilirubin, phototherapy, and brain development warrant further investigation. Identification of physiological risk factors associated with selective vulnerability of certain brain regions at near-term age may clarify the etiology of neurodevelopmental impairment and inform neuroprotective treatment for VLBW preterm infants.
•Biomarkers of inflammation in preterm infants correlated with brain abnormalities detected on near-term structural MRI.•Biomarkers of inflammation in preterm infants correlated with near-term WM microstructure assessed on DTI.•Signal abnormalities observed on near-term structural MRI correlated with increased thalamus MD.
PMCID: PMC4110350  PMID: 25068107
MRI; Diffusion tensor imaging; White matter microstructure; Brain development; Risk factors; Preterm infants; VLBW, very-low-birth-weight; GA, gestational age; PMA, post-menstrual age; DTI, diffusion tensor imaging; FA, fractional anisotropy; MD, mean diffusivity; CC, corpus callosum; IC, internal capsule; ALIC, anterior limb of the internal capsule; PLIC, posterior limb of the internal capsule; GloP, globus pallidus
25.  Association of Early Preterm Birth with Abnormal Levels of Routinely Collected First and Second Trimester Biomarkers 
American journal of obstetrics and gynecology  2013;208(6):492.e1-492.e11.
To examine the relationship between typically measured prenatal screening biomarkers and early preterm birth in euploid pregnancies.
Study Design
Included were 345 early preterm cases (< 30 weeks) and 1,725 controls drawn from a population-based sample of California pregnancies that all had both first and second trimester screening results. Logistic regression analyses were used to compare patterns of biomarkers in cases and controls and to develop predictive models. Replicability of the biomarker-early preterm relationships revealed by the models was evaluated by examining the frequency and associated adjusted relative risks (RRsadj) for early preterm birth and for preterm birth in general (< 37 weeks) in pregnancies with identified abnormal markers compared to those without these markers in a subsequent independent California cohort of screened pregnancies (n = 76,588).
The final model for early preterm birth included first trimester pregnancy-associated plasma protein A (PAPP-A) ≤ the 5th percentile, second trimester alpha-fetoprotein (AFP) ≥ the 95th percentile, and second trimester inhibin (INH) ≥ the 95th percentile (odds ratios 2.3 to 3.6). In general, pregnancies in the subsequent cohort with a biomarker pattern found to be associated with early preterm delivery in the first sample were at an increased risk for early preterm birth and preterm birth in general (< 37 weeks) (RRsadj 1.6 to 27.4). Pregnancies with two or more biomarker abnormalities were at particularly increased risk (RRsadj 3.6 to 27.4).
When considered across cohorts and in combination, abnormalities in routinely collected biomarkers reveal predictable risks for early preterm birth.
PMCID: PMC3672244  PMID: 23395922
Preterm Birth; Prenatal Screening; Biomarkers

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